1. Technical Field
The present invention relates to a semiconductor integrated circuit, and more particularly, to an output circuit of a semiconductor apparatus.
2. Related Art
A decoupling capacitor which can maintain a constant voltage and reduce power noise is coupled to an output circuit of a semiconductor apparatus.
In general, since output circuits operate at high frequencies of up to hundreds of MHz or more, then MOS capacitors which exhibit an excellent characteristics in high frequency bands can be used as decoupling capacitors. In the case where an output circuit uses a MOS capacitor as a decoupling capacitor, then a Q-factor of a resonant frequency is likely to increase and power noise is likely to increase in low frequency bands. Hence, data outputted from output circuits that uses MOS capacitors as decoupling capacitors may result being damaged or compromised.
On the other hand, an output circuit that uses an electrolytic capacitor as a decoupling capacitor, instead of a MOS capacitor, is expected to exhibit excellent characteristic in terms of power noise reduction at low frequency bands, but is likely to exhibit increased power noise at high frequency band and thus is prone to electromagnetic interference (EMI).